At a medical site, an image of a patient is captured by a medical imaging apparatus such as an X-ray CT (Computed Tomography) apparatus, an MRI (Magnetic Resonance Imaging) apparatus, or a PET (Position Emission Tomography) apparatus. By viewing the captured medical image in detail, an anatomical structure of various types of target sites ((organs) in the body of the patient and functional information therefor are obtained, and the information is used in diagnosis and treatment.
Within the various types of target sites that comprise in a human body, there is a type of organ that moves with respect to target sites in the periphery thereof. For example, the lungs move in accordance with respiratory movement, and the heart moves to cause the circulation of blood in a body. Even for the same target site, it is known that due to its structure or the presence absence of a lesion, movement (a direction of a movement or an amount of a movement) relative to the periphery differs depending on a position in the target site or on its surface (hereinafter, referred to as a position-within-target-site).
There is a demand from users (a doctor or the like) to be able to recognize a position-within-target-site having an abnormal movement to discover a lesion, by visualizing, from medical images, differences in the direction of a movement at the position-within-target-site that is made to be a target, or in the amount of the movement (hereinafter, referred to as movement information). For example, there is a demand to be able to specify an adhesion position in a surface of a lung from medical images by visualizing differences in movement information according to respiratory movement of a lung, with respect to differences in position on the surface of the lung. In Japanese Patent Laid-Open No. 2012-213604, a technique of specifying a lesion portion from a medical image, and calculating a level of infiltration to the periphery of the lesion portion from relative movement information of the lesion portion and peripheral portions thereof is disclosed.
However, in the technique recited in Japanese Patent Laid-Open No. 2012-213604, it is not possible to visualize a difference in movement information in a difference in position in the lesion portion. In other words, even if this is applied, replacing the lesion portion recited in Japanese Patent Laid-Open No. 2012-213604 with a target site, it is not possible to visualize differences in movement information in differences in position-within-target-site for the target site, and the user is not able to recognize a position-within-target-site that has abnormal movement information in the target site.